constants: Increase CANARY_TYPE build timeout.

This RELEASE BRANCH ONLY change increases the timeout for canary type
builds to be 12 hours.

BUG=chromium:558781
TEST=cbuildbot/run_tests

Change-Id: I50d00e40841ab2b0bbb3d633a35daf4071450044
Reviewed-on: https://chromium-review.googlesource.com/314885
Tested-by: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Queue: Don Garrett <dgarrett@chromium.org>
(cherry picked from commit cd3dbd6d8a864f4dc0ef511d440a103e765c8bfa)
Reviewed-on: https://chromium-review.googlesource.com/314836
1 file changed